Abstract: A method for estimating a runtime of a query of a data repository may abstract, extract, or otherwise generate one or more parameters of the query. Thereafter, the abstracted parameters may be associated with one or more statistical query records. From these statistical query records, a query runtime may be estimated. Related apparatuses, computer program products, and computer systems are also described.

Abstract: Systems and techniques for the hybrid provision of data are described. In one aspect, a system includes a first collection of information stored in accordance with a reporting data model, a second collection of information setting forth a collection of one or more additive delta records, and an analytic engine to perform queries on the first collection of information and the second collection of information to yield an aggregated result set that is based on the contents of both the first collection of information and the second collection of information. The additive delta records each include a numeric value that characterizes the magnitude of a change to a numeric measure in the first collection and identification information that identifies the numeric measure in the first collection. The identified numeric measure is no longer current.

Abstract: Systems and techniques for sequencing transactions and operations. In one aspect, an article includes one or more machine-readable media storing instructions operable to cause one or more machines to perform operations. The operations include identifying a delta of a first data store, and replicating the delta, including the transaction, to a second data store. The delta comprising a collection of changes to the first data store since a previous replication. The delta includes a transaction that began before the previous replication but did not commit before the previous replication replicated data from the first data store.

Abstract: Systems and techniques for handling potentially ambiguous joins. In one aspect, an article includes a machine-readable medium storing instructions operable to cause one or more machines to perform operations. The operations include receiving a query that includes an ambiguous join of at least two data tables in a relational database, reducing a number of join partners in at least one of the at least two data tables by locally aggregating first data on a first side of the ambiguous join, and joining the locally aggregated first data and second data from the second side of the ambiguous join on a join condition in the ambiguous join. The ambiguous join identifies fewer fields than necessary to define a unique key between the data tables and the unidentified fields are omitted from any global unique restriction in the query.

Abstract: Systems and techniques for mapping data structures in a data processing environment to help ensure the accessibility of stored information. In one implementation, an article includes a machine-readable medium storing instructions. The instructions are operable to cause one or more machines to perform operations. The operations include receiving a first data storage schema in which a characteristic in a first dimension table is mapped by a first table and a second table and generating a second data storage schema. The first table maps the characteristic to a first object that include attributes to which time information is irrelevant to data processing activities and the second table maps the characteristic to a second object that include attributes to which time information is relevant to data processing activities.

Abstract: A system, method and computer program product for linking multidimensional data sources in a relational database using database joins are disclosed. Attributes from a join query are filtered. The attributes include characteristics and restrictions of the join query. A subset of the attributes that are relevant to the multidimensional data source are extracted. A partial join query is generated from the extracted subset of the attributes. The partial join query includes characteristics and restrictions that are relevant to the multidimensional data source. It makes use of aggregated data defined for the multidimensional data source if appropriate.

Abstract: A method and system for linking the contents of two or more at least partially time-independent tables in a multidimensional data source are disclosed. A join operation is generated for the two or more at least partially time-independent tables. The join operation includes a query instruction that is executable on the multidimensional data source, and the query instruction has at least one time attribute. A pseudo time dependency between the two or more at least partially time-independent tables is determined. A time interval for the join operation is generated based on the pseudo time dependency. The join operation is then executed using the time interval as the at least one time attribute.

Abstract: A query having multiple parts may be processed to form an intermediate results set. This intermediate results set may be partitioned into a plurality of groups. Thereafter, the groups may be sorted into a plurality of containers so that each container contains data sufficient to calculate one requested result in the multipart query. Related techniques, apparatuses, systems, and computer program products are also described.

Abstract: A method for estimating a runtime of a query of a data repository may abstract, extract, or otherwise generate one or more parameters of the query. Thereafter, the abstracted parameters may be associated with one or more statistical query records. From these statistical query records, a query runtime may be estimated. Related apparatuses, computer program products, and computer systems are also described.